|Cite this article as:|
|Yun Zhao, Juping Tu, Liangxian Chen, Junjun Wei, Jinlong Liu, and Chengming Li, Toughness enhancement of single-crystal diamond by the homoepitaxial growth of periodic nitrogen-doped nano-multilayers, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2497-1|
Periodic nitrogen-doped homoepitaxial nano-multilayers are grown by microwave plasma chemical vapor deposition. The residual time of gases (such as CH4 and N2) in the chamber is determined by optical emission spectroscopy to determine the nano-multilayer growth process, and thin, nanoscale nitrogen-doped layers are obtained. The highest toughness of 18.2 MPa m1/2 under a Young’s modulus of 1000 GPa is obtained when the single-layer thickness of periodic nitrogen-doped nano-multilayers is about 96 nm. Compared with that of a high-pressure high-temperature seed substrate, the fracture toughness of periodic nitrogen-doped nano-multilayers is greater than twice that of the seed substrate. Alternating tensile and compressive stresses are derived from periodic nitrogen doping; hence, the fracture toughness is significantly improved. Single-crystal diamond with a high toughness demonstrates wide application prospects for high-pressure anvils and single-point diamond cutting tools.